Clamping ring release mechanism



Deg 3 1953 R. s. BRASHEARS 3,115,335

CLAMPING RING RELEASE MECHANISM Filed March 12, 1958 :5 Sheets-Sheet 142 m m a; 2

RICHARD 8. BRA SHEARS INVENTOR.

ATTORNEYS Dec. 31, 1963 R. s. BRASHEARS 3,115,836

CLAMPING RING RELEASE MECHANISM Filed March 12. 1958 3 Sheets-Sheet 2III/II RICHARD 8. ERAS R8 INVENT BY Q/Ba'x ATTORNEYS 1963 R. s.BRASHEARS 3, 3

CLAMPING RING RELEASE MECHANISM Filed March 12. 1958 3 Sheets-Sheet 3FIG. 5.

RICHARD 5. BRASHEARS IN VEN TOR.

ATTORNEYS 3,l libii 'o Patented Dec. 31, lilti S, Ser. No. 721,672 8Qlaims. (Cl.

This invention relates to release mechanisms, and more particularly to amechanism for effecting inflight release of a booster rocket from amissile.

Certain missile-booster combinations are stored in readiness forlaunching in a coupled state, that is, with the e clamp-e l to thebooster so that a minimum amount or" preparation time is required fordelivery to the launcher. As described in US. patent application No.594,067, filed lune 26, l956, by v ll. Goss et al., elating to a GuidedMissile, the missile is unclamped from the booster as the missilebooster combination leaves the launcher; however, combination remainscoupled by the force of the booster impulse. During flight, as thebooster thrust decays and the force between the missile and boosterapproaches zero, separation conditions occur, rate of separation ofcourse being dependent on the rate of booster thrust decay. Many flightshave indicated successful separation; however, of the portion of flightsthat have resulted in failure, a considerable percentage can possibly beattributed to unsuccessful separation of the booster from the missile.Test data has indicated,

especially in the case of flight failures, that separa.'on was themissile the booster.

One possible explanation advanced for the recontect was that impactbetween the missile and booster was due to the combination of a slowbooster tail-oil and pressure oscillations in the missile diiluser. Itis belie ed that this recontact caused such misalignment of the missileas to result in flight instability.

Although it cannot be stated that a slow booster tailoil woulddefinitely result in a flight failure, it is apparent that with anunlocked nissire-booster jo and slow booster tail-off, the misse-booster combi.

tion is on the verge of instability at separation, and the destabilizingforces will have a greater time interval in which to act.

As a solution to this problem, it was determined that since the missileand booster where held toge her before launching by a clamp ring, whatwas required was a means of releasing the clamp ring at end of the boostphase rather than at beginning, i.e., upon launching. Fun thermore, ifthe clamp ring were released slightly later than the time separationwould normally occur if tli missile and booster were not clam ncdtogether, a tension force would be built up across the missile-boosterjoint as a result of the decay of thrust below the drag diterentialbetween the missile and the booster. This tension force would insurethat separation proceed rapidly thus shortening the time of ap icationof any destabilizing force by the booster on the missile, and would tendto eliminate damaging rec ntact between the missile and the booster.

It is an object of this invention, therefore, to provide means foreffecting, at a time most favorable for rapid separation, release of aclamping ring holding together a missile and a booster.

It is also an object of this invention to provide means for effecting,as rapidly as possible, release of a clamping ring holding together amissile and a booster to mitigate the effects of any destabilizingforces imposed by the booster on the missile.

It is a further object of this invention to provide means for effectingat the end of the booster thrust phase, in-

flight release of a clamping ring holding together a missile and abooster.

Still another obiect of this invention is to provide means forpreventing damaging recontact of a missile and a booster at separation.

Other objects and many of the attendant advantages of this inventionwill readily be anpreciated as the same becomes understood by referenceto the following detailed description when considered in connection withthe accompanyin drawings, wherein:

FIG. 1 is a side elevation of a missile and booster held together by aclamping ring, showing the location of the release mechanism;

FIG. 2 is a cross section on line 2-2 of FIG. 1 showing the generalarrangement of the release mechanism and details 05 the clamping ring;

' FIG. 3 is a longitudinal section of the sensing cylinder; 4 is anenlarged section of the explosive cylinder 4-4 of FIG. 2; and

. 5 is a cross section of the explosive cylinder on line 55 of PEG. 4-.

Briefly, the present invention contemplates a sensing cylinder mountedon the booster of a missile-booster combination and actuated by pressurebled from the booster chamber. The piston of sensinx cylinder, inresponding to a drop in booster pressure at boost phase termination,actuatcs a microswltch which closes a circuit from a thermal battery toan explosive containing cylinder that is also mounted on the booster.The l -ter cylinder, upon detonation, releases a sciss rs mechanismholding together a clamp 3 ring that couples the missile to the booster.

Reterr lg now to the drawings in greater detail, FIG. 1 shows a missie-booster combination 1 having a missile 2 and a booster rocket 3 holdtogether by a clamping ring assembly A release mechanism 5 constitutingthe present invention is mounted on the forward end of the booster 3.

The clamping ring assembly 4 is disclosed in US. patent application No.594,067, filed June 26, 1956, by W. H. Goss et al. for a Guided Missile,and as seen in FIG. 2, includes a pair of companion semicircular ringsections 6 each having an internally threaded fitting '7 secured to oneend thereof. A right and left screw link 8 engages each or" the fittings'7 to connect the two ring sections 6. A hexagonal head 9 is provided ateach end of the link S to facilitate wrenching for adjusting purposes.On the other end of each of the ring sections 6 is secured a bracket illhaving a pair of apertured yokes ll formed thereon. A scissors hinge212, having its two arms 11% and 14- pivotally connected by a pin 15, ispivotally mounted on the brackets 159 by pins 16. The scissors hinge l2permits concentric opening of the ring sections 6 to uncouple thebooster 3 from the missile 2. To insure positive opening of these ringsections, leaf springs 17 are mounted on the inner surface thereof andbear against the missile-booster combination and tend to force the ringsections 6 outwardly. The end portions of the scissors arms 13 and M,respectively, are formed with lateral extensions 13a and 14a and areheld together by an exploivc cylinder assembly 1&5), to be hereinafterdescribed.

As best seen in FIGS. 2 and 3, the release mechanism 5 includes asensing cylinder assembly 29 mounted on the booster 3 by a bracket 22.The cylinder assembly 26 comprises a cylinder 24 having a first chamberand a second chamber 2?. A wall 333 is positioned between the twochambers 26 and 2% and has an aperture 32. extending therethrough. Anend cap 34 threadably engages and closes the cylinder 2-4 at the endnearest the first chamber 26. An O-ring 35 is positioned between thecylinder 24 and end cap 34 for sealing purposes. A nipple 36 having anaperture 38 extending theretnrough is formed on the end cap 34 and isconnected to a tube 39 which transmits pressure from a chamber (notshown) of the booster 3. A head cap threadably engages and closes theend of the cylinder nearest the second chamber A piston 42 is located inthe first chamber 26 and has a stem 44 extending through the aperture 32of the wall 3% The stem 44 is long enough to extend the full length ofthe cylinder 24 and t trough an aperture 46 in end wall 48 of the headcap 4%. An annular groove St is formed in the piston 42 to contain asuitable packing 52. A shoulder 54 is provided on the stem 44 and bearsagainst bearing plate 56. A spring 53 is interposed between the bearingplate 56 and the end wall 48 of the head cap 49.

Attached to the head cap by bolts 6% is a housing 64 in which is mounteda microswitch 66 by means of screws 67. A bore 63 in registry with theaperture 46 is provided in the housing 64 for receiving the extension ofthe piston stem and for containing a retainer 79. A vent hole '72 isformed in end wall '74 and communicates with the bore 68. Themicroswitch 66 is a normally closed switch and is actuated by a plunger76 which is housed in a crossbore 78 formed in the housing 64. It willbe seen that the relationship of the piston stem 44 to the crossbore 78is such that the stem in its uppermost position is clear of thecrossbore. This arrangement permits the retainer 7% to assume a positionacross the crossbore 78 to hold the plunger 76 down, thus keeping themicroswitch 66 open. A detent is provided for maintaining the retainer7% in this position by a spring loaded ball 80 riding in a groove 82formed on the retainer. The ball 84 is located in an aperture 84 in thehousing 64 and is held down by a spring 86 and a machine screw 2%. Asecond groove 95 is formed in the retainer 79 to provide a second detentposition and is located so that when the retainer is in this seconddetent position, the retainer will be clear of the crossbore "78. Itshould be noted that the bore 68 should be of sufiicient length toaccommodate the retainer 70 when the latter is in the second detentposition.

As previously mentioned, booster chamber pressure is transmitted to thecylinder assembly 29 by means of the tube 39. This transmitted pressureacts on the piston 42 to move it against the force of the spring 58until the end of the stem 44 contacts the retainer 70 in the housing 64.As the piston continues its movement, the retainer 76) is urged out ofits first detent position, and the stem 44 eventually displaces theretainer sufficiently so that the microswitch plunger 76 Will be helddown by the stem 44 rather than by the retainer. The retainer 70, inbeing displaced, moves into contact with the end wall 74 and at the sametime moves into the second detent position, that is, the ball 80 engagesin the groove 90.

At termination of the boost phase, as the booster chamber pressuresubsides, the piston 42. begins to reverse its movement, since the forceof the spring 53 will again predominate. As the piston stem 44 retracts,the retainer 7h will remain stationary by reason of the engagement ofthe ball 8% in the groove @i in the second detent position. Thus, theplunger 76 will be released when the stem 44 clears the crossbore '78.Release of the plun er actuate-s the microswitch 66 to close a circuitin cable 79 between a thermal battery )4 and the explosive cylinderassembly Ill-ti. Since it is desired that the microswitch 66 be actuatedat a certain known value of booster pressure, the spring 58 should havea proper spring constant. In order to allow for any small inaccuraciesin calibration of the spring, shims 92 may be utilized between the headcap 40 and the housing 64 for varying the loading on the spring.

The thermal battery 94- is mounted on the booster and is provided with asolid electrolyte that is melted Whenever it is desired to activate thebattery. This type battery has a much longer shelf life than an ordinarybattery and is particularly suitable for use on missiles or rockets thatspend much time in storage.

Th t explosive cyl r assembly H ll is mounted on the booster 3, and asshown in FIGS. 2 and 4, restricts movement of the scissors hinge 12 tomaintain the clamping ring sections 6 in a clamped position. As bestseen in FIG. 4, the explosive cylinder assembly tilt) comprises acylinder Iii-2 having a piston 104 therein. One end of the cylinder lllZis formed with an internally threaded portion 1636 into which is screweda housing 188, a diaphragm it being compressed between the cylinder andthe housing. The housing 11638 is provided with recesses lit) and 11.2at its ends, and interposed between the two recesses is a wall 114having two apertures 116 extending therethrough. The two apertures arecounterbored to form an enlarged diameter portion 118 and threads areprovided on a part of the enlarged diameter portion 113 nearest therecess 11%. At its opposite end the housing is threaded at 122 to receive a nut 124.

Two squibs 126 are contained in the housing the; and conform generallyto the configuration or" the apertures 116 and the unthreaded part ofthe enlarged diameter portion 118. A plastic insulating sleeve 12? isinterposed between the housing lttltl and the squids at the aperture116, a projecting portion 123 of each of the squibs 126 extendingthrough the aperture 116 into the recess 112 and being provided with athin-walled brass cap 130 having external threads formed thereon. Twoplugs 132, each having an aperture 134 extending therethrough and havingexternal threads thereon, are screwed into the threaded part of theenlarged diameter portion 113, and an explosive substance 136, such asblack cannon powder, is contained in the recess ill) adjacent the plugs132 and is held in place by a diaphragm 138.

As shown in FIGS. 4 and 5, an electrical contact 146 having anexternally threaded portion 142 and an internally threaded portion 144,is screwed into the housing A circular insulating spacer 146 ispositioned against the wall 114 of the housing 168 in recess 112 and isproperly apertured to permit the projecting portion of squibs 126 andthe contact 14% to project therethrough. An apertured contact plate 152is positioned against the spacer 146 and is secured by two slottedcontact nuts 156 that engage the threaded brass caps 134 on the squibs126. As seen in FIG. 5, the plate 152 is so constructed that whenproperly positioned, it will not come into contact with the electricalcontact 140. Two terminals 158 are provided on the plate 152 forfacilitating attachment of wires 162. A screw 164 ongages the internallythreaded portion 144 of the contact 149 for securing a ground wire 166.

A cap 168 closes the recess 1112 of the housing 168 and is clamped tothe housing by the tightening of the nut 124 down on a flange 170 formedon the cap, a pin 1'71 projecting from the end of the housing 1458 toengage in a slot 172 formed in the flange 17% for locating purposes. Asetscrew is provided on the nut 124 to prevent undesired movementthereof. The top of the cap 163 is formed by an electrical connector 174soldered there to. After the other ends of the wires 162 and 166 areattached to the connector 174-, potting compound (not shown) is injectedthrough an aperture 1'75 in the wall of the cap tea to fill the spaceformed by the recess 112 and the cap.

Referring again to FIG. 4, it will be see that the piston M4 is ofhollow cylindrical construction and is formed with an outer rim 1185ithat slides against the inside of cylinder Wall 182, an end wall 184 ofthe cylinder 192 being provided with an aperture 186 to support theother end of the piston 1634 and to permit the latter to slidably extendtherethrough. Thus the piston is constrained to move within the limitsimposed by the diaphragm 10% and the end wall 184. An aperture 138 isdrilled through the cylinder wall 182 for venting purposes. A projectingportion HQ of the cylinder i492 extends beyond the end Wall 184 and asviewed in FIG. 2 is formed with a longitudinal slot 192 that issubstantially T-shaped.

It will be remembered that the explosive cylinder assembly It'llrestricts movement of the scissors hinge 1? to maintain the clampingring sections 6 in a clamped position. FIGS. 2 and 4 show the cylinderassembly 100 mounted on the booster 3 adjacent the scissors hinge 12. insuch manner that the projecting portion 1% clamps together the two arms13 and 14 by engagement of the extensions 13a and 14a in the T-shapedslot 1%. While the extensions 15a and 14;: are engaged in the slot 192,the piston 1%, by contact with the arm ends, is forced into the cylinder102 until the 18'!) is bearing lightly against the diaphragm 1499. Itwill be seen then, that when the explosive substance 136 is detonated,the piston 104 will tend to be forced to the other end of the cylinder.However, because the piston bears against the scissors hinge 12-, thecylinder 1532 will be displaced from its original position, thus freeingthe scissors hinge arms 13 and 14 to allow the ring sections e to springfree of the missile-booster combination.

For the purpose of preventing premature release of the hinge arms 13 andIl a, a pin 194 is inserted through apertures in the cylinder 192 andthe hinge arms to avert withdrawal of the extensions 13a and 14a fromthe slot 192.

In use, the missile 2 and the booster 3 are conveyed to the launcher ina coupled state, being held together by the clamping ring assembly 4. Aspart of the procedure for preparing the missile-booster for launching,the pin 19 i is withdrawn from its position where it is locking thescissors arms 13 and 1-: in the T-sl'rped slot 192 of the explosivecylinder assembly 18%. At about the same time the electrolyte of thethermal battery 94 is melted by an independent heating circuit toactivate the battery.

At launching, upon ignition of the booster rocket, the increasedpressure in the booster chamber acts through the tube 39 to move thepiston 42 against the force of the spring 58, thereby causing the pistonstem 44 to displace the retainer it? in holding the plunger 76 down tokeep the microswitch es open. This condition is maintained throughoutthe boost phase until the booster thrust decays to a certainpredetermined value. When this occurs, and the booster pressure drops,the force of the spring 58 returns the piston 42 to its originalposition thus allowing the plunger 76 to be released. This actuates themicroswitch 65 which in turn closes firing circuits between the thermalbattery 96 and each of the squibs 126. The squibs then detonate theexplosive substance 136 to displace the cylinder 182 from its clampingposition which frees the arms 13 and 1d of the scissors hinge l2.Disengagement of the scissors hinge arms from the cylinder 1&2 permitsthe clamping ring sections 6 to release under the force of the springs17 thereby uncoupling the booster 3 from the missile 2.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

\Vhat is claimed is:

l. In combination with a missile and a booster rocket coupled in tandemby a releasable clamping ring, a mechanism on said booster rocket foreffecting in-fiight release of said clamping ring, comprising, meansengageable with said ring and including a clamp for constraining saidring to a clamping position, said means being actuable by an electricalimpulse to release said clamp from constraint of said ring, a source ofelectrical energy and a switch coupled thereto, said switch beingoperable to transmit said electrical impulse to said means, and secondmeans coupled to said first mentioned means and including a sensingcylinder having a spring loaded piston and a retainer, a detent for saidretainer, said piston and retainer being engageable with said switch,said cylinder being responsive to pressure within said booster andoperable against the force of said spring loaded piston and saidretainer at a predetermined value of said pressure to move said pistoninto an armed position wherein said mechanism is ready to release saidclamping ring, said cylinder also being responsive subsequently atanother predetermined value of said pressure to operate said switch.

2. The combination as claimed in claim 1, wherein said first meansincludes additionally an explosive device connected to said clamp anddetonable upon receipt of said impulse to disengage said clamp from saidring.

3. In a releasable clamping ring arrangement for coupling a missile anda booster, a mechanism for efiecting in-fiight release of said clampingring, comprising, means engageable with said ring and including a clampfor constraining said ring to a clamping position, said means beingactuable upon receipt of an electrical impulse from the booster torelease said ring, a source of electrical energy, a switch and circuitryto electrically couple said source to said means, and a sensing cylinderengageable with said switch and responsive to pressure within saidbooster, said cylinder including a spring loaded piston and a retainer,said piston and retainer being engageable with said switch, a detent forsaid retainer, said cylinder being operable against the force of saidspring loaded piston and retainer at a predetermined value of saidpressure to place said mechanism in an armed condition wherein saidmechanism is ready to release said clamping ring, said cylinder alsobeing operable subsequently at another predetermined value of saidpressure to operate said switch.

4. The apparatus as recited in claim 3, wherein said means includesadditionally an explosive device connected to said clamp and detonableupon receipt of said impulse to displace said clamp from engagement withsaid ring.

5. In combination with a missile and a booster, and a releasableclamping ring for coupling said missile and booster in tandemrelationship, said clamping ring having release arms, a releasemechanism on said booster for eilecting in-flight release of saidclamping ring, comprising, a retaining member slidably engageable withsaid release arms and tending to prevent release of said ring, acylinder connected to said member and having an explosive chargetherein, said charge being detonable upon receipt of a signal todisplace said member from engagement with said release arms, a battery,a switch connected to said battery, a sensing cylinder including aspring loaded piston and a retainer, a detent for said retainer, saidpiston and retainer being engageable with said switch, said cylinderbeing responsive to gas pressure within said booster and operableagainst the force of said spring loaded piston and retainer at apredetermined value of said pressure to place said release mechanism inan armed condition wherein said mechanism is ready to release saidclamping ring, said cylinder also being operable subsequently and atanother predetermined value of said pressure to close said switch toproduce said signal, and circuitry to transmit said signal from saidbattery to said explosive cylinder.

6. In combination with a missile and a booster, and a releasableclamping ring coupling said missile and booster in tandem relationship,a mechanism on said booster for elfecting in-dight release of saidclamping ring, com-pris ing, constraining means engageable with saidring and including a clamp for holding said ring in a clamped position,a battery, a switch connected to said battery and actuable toelectrically couple said battery and said constraining means, a sensingcylinder including a spring loaded piston and a retainer, a detent forsaid retainer, said piston and retainer being engageable with saidswitch, said cylinder being responsive to pressure in said booster andbeing operable against the force of said spring loaded piston andretainer at a predetermined value of said pressure to place saidmechanism in an armed condition wherein said mechanism is ready torelease said clamping ring, said cylinder also being operablesubsequently and at another predetermined value or" said pressure toactu- 7 ate said switch, whereby said electric signal is transmitted tosaid constraining means, thereby causing said constraining means toactuate and expel said clamp from engagement with said ring.

7. The apparatus recited in claim 6 wherein said constraining meansincludes additionally an explosive cylinder detonable upon receipt ofsaid electric signal.

8. The apparatus recited in claim 6 wherein said sensing cylinderincludes a piston stern on said spring loaded piston and engageable withsaid retainer, said retainer being engageable with said switch to keepsaid switch in an open position and said mechanism in an unarmedcondition, said piston stem also being engageable with said switch tokeep said switch in the open position and said mechanism in the armedcondition, said mechanism being in the unarmed condition until saidfirst predetermined value of said booster pressure is attained, wherebysaid first predetermined value of said pressure urges said piston andpiston stem to replace said retainer in engagement with said switchthereby placing said mechanism in the armed condition, and whereby saidsubsequent and other predetermined value of booster pressure causes saidspring loaded piston to withdraw said stem from engagement from saidswitch, there-by actuating said constraining means.

References Cited in the file of this patent UNITED STATES PATENTS2,498,040 Jordan et al Feb. 21, 1950 2,779,283 Baughman Jan. 29, 19572,809,584 Smith Oct. 15, 1957 2,833,494 Parker et a1. May 6, 1958

1. IN COMBINATION WITH A MISSILE AND A BOOSTER ROCKET COUPLED IN TANDEMBY A RELEASABLE CLAMPING RING, A MECHANISM ON SAID BOOSTER ROCKET FOREFFECTING IN-FLIGHT RELEASE OF SAID CLAMPING RING, COMPRISING, MEANSENGAGEABLE WITH SAID RING AND INCLUDING A CLAMP FOR CONSTRAINING SAIDRING TO A CLAMPING POSITION, SAID MEANS BEING ACTUABLE BY AN ELECTRICALIMPULSE TO RELEASE SAID CLAMP FROM CONSTRAINT OF SAID RING, A SOURCE OFELECTRICAL ENERGY AND A SWITCH COUPLED THERETO, SAID SWITCH BEINGOPERABLE TO TRANSMIT SAID ELECTRICAL IMPULSE TO SAID MEANS, AND SECONDMEANS COUPLED TO SAID FIRST MENTIONED MEANS AND INCLUDING A SENSINGCYLINDER HAVING A SPRING LOADED PISTON AND A RETAINER, A DETENT FOR SAIDRETAINER, SAID PISTON AND RETAINER BEING ENGAGEABLE WITH SAID SWITCH,SAID CYLINDER BEING RESPONSIVE TO PRESSURE WITHIN SAID BOOSTER ANDOPERABLE AGAINST THE FORCE OF SAID SPRING LOADED PISTON AND SAIDRETAINER AT A PREDETERMINED VALUE OF SAID PRESSURE TO MOVE SAID PISTONINTO AN ARMED POSITION WHEREIN SAID MECHANISM IS READY TO RELEASE SAIDCLAMPING RING, SAID CYLINDER ALSO BEING RESPONSIVE SUBSEQUENTLY ATANOTHER PREDETERMINED VALUE OF SAID PRESSURE TO OPERATE SAID SWITCH.